按钮点击不工作使用ASP.净c#

在本地工作正常，但当我在肝脏服务器上注册时，有些时候注册是重定向到成功页面，有些时候没有重定向，也没有得到任何错误消息。注册表格是非常大的，所以，我没有把所有的设计，代码，但我已经从每个块代码。根据我的面板是问题可能是，但另一件事我必须观察，如果页面不是注册，然后我重新加载相同的页面，然后填写所有的细节，然后它的提交。

页面加载代码:

  BusinessLogic bl = new BusinessLogic();
BusinessObject bo = new BusinessObject();
protected void Page_Load(object sender, EventArgs e)
{
    HtmlGenericControl body = (HtmlGenericControl)Master.FindControl("MasterpageID");
    body.Attributes.Add("class", "fifth");
    //to restore password field when page refreshes
    txt_Password.Attributes.Add("value", txt_Password.Text);

}

设计代码:

Nationality:<asp:DropDownList ID="ddl_Nationality" runat="server" CssClass="dropdown" AppendDataBoundItems="true"
            AutoPostBack="true" OnSelectedIndexChanged="ddl_Nationality_SelectedIndexChanged">
                <asp:ListItem Text="Select" Value="0"></asp:ListItem>
                    <asp:ListItem Text="Indian" Value="Indian"></asp:ListItem>
                    <asp:ListItem Text="Expatriate" Value="Expatriate"></asp:ListItem>
          </asp:DropDownList>

    Title: <asp:DropDownList ID="ddl_Title" runat="server" CssClass="dropdown" AppendDataBoundItems="true">
    <asp:ListItem Text="Select" Value="0"></asp:ListItem>
        <asp:ListItem Text="Mr." Value="Mr."></asp:ListItem>
        </asp:DropDownList>
    Name:  <asp:TextBox ID="txt_Name" runat="server" CssClass="textfield_new1" MaxLength="20"></asp:TextBox>
    </ContentTemplate>
    </asp:UpdatePanel>

     <asp:UpdatePanel ID="UpdatePanel3" runat="server">
      <ContentTemplate>
    <table>
    <tr>
    <td>
    Country:    <asp:DropDownList ID="ddl_Country" runat="server" CssClass="dropdown">
            <asp:ListItem Text="Select" Value="0"></asp:ListItem>
                  </asp:DropDownList>
    </td>
    </tr>
    </table>
    </ContentTemplate>
    </asp:UpdatePanel>

    <table>
    <tr>
    <td>
        <asp:UpdatePanel ID="UpdatePanel5" runat="server" >
                <ContentTemplate>
                   Total Experience:        <asp:DropDownList ID="ddl_years" runat="server" AutoPostBack="true" CssClass="Exp"
                   OnSelectedIndexChanged="ddl_years_SelectedIndexChanged">
                       <asp:ListItem Value="0">Year</asp:ListItem>
               <asp:ListItem Value="1">0</asp:ListItem>
                    <asp:ListItem Value="2">1</asp:ListItem>
                        <asp:ListItem Value="3">2</asp:ListItem>
                        <asp:ListItem Value="4">3</asp:ListItem>
             </asp:DropDownList>
                  <asp:DropDownList ID="ddl_months" runat="server" CssClass="Exp"
               Enabled="false">
                   <asp:ListItem Selected="True" Value="0">Month</asp:ListItem>
              <asp:ListItem Value="1">0</asp:ListItem>
              </asp:DropDownList>
               </ContentTemplate>
                </asp:UpdatePanel>
             </td> </tr>
    </table>

        <table>
    <tr>
    <td>
            <asp:UpdatePanel ID="UpdatePanel4" runat="server">
                <ContentTemplate>
        <cc1:CaptchaControl ID="CaptchaControl1" runat="server" CaptchaBackgroundNoise="None"
            CaptchaHeight="40" CaptchaLength="5" CaptchaLineNoise="None" CaptchaMaxTimeout="240" 
        CaptchaMinTimeout="5" FontColor="111, 109, 85" Width="325px" CaptchaWidth="300"
        CssClass="textarea_captha" />
            </ContentTemplate>
        </asp:UpdatePanel>
    </td></tr>
        <tr><td>
    Enter Text as you See:<asp:TextBox ID="txtCaptcha" runat="server" CssClass="textfield_new1"></asp:TextBox>
        </td></tr>
    </table>
    <table>
    <tr><td>
    <asp:LinkButton ID="imgbtn_Submit" runat="server" ValidationGroup="reg" CssClass="submitbtn"
    </td></tr>
    </table>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
                <asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="images/spacer.gif" />
                <cc1:ModalPopupExtender ID="ModalPopupExtender1" TargetControlID="ImageButton1" PopupControlID="Pnl_popup1"
                BackgroundCssClass="modalBackground" Drag="true" PopupDragHandleControlID="Pnl_popup1"
                                                    runat="server">
                    </cc1:ModalPopupExtender>
                    <asp:Panel ID="Pnl_popup1" runat="server">
                                                //pop design code is here
                                                    </asp:Panel>
                </ContentTemplate>
                </asp:UpdatePanel>